The present invention relates generally to welding-type machines and, more particularly, to a light filtering assembly that improves detectability of light emitted by a light-emitting device or readability of a display. In this regard, the present invention is further directed to reflecting, refracting, absorbing, or otherwise dissipating ambient light incident on an indicator or display so as to enhance detectabilty of the emitted light or readability of the display when the light-emitting device or display is subjected to relatively intense ambient light, such as direct sunlight.
Welding-type machines, such as welders (power sources), plasma cutters, heaters, aircraft ground power units, wire feeders, generators, and the like, typically have liquid crystal displays (LCDs)or light-emitting diodes (LEDs) to provide visual indicators to a user regarding operating conditions of the machine. For example, an engine-driven generator may include LEDs for an engine hour meter, a low fuel indicator, a low engine oil pressure indicator, a low battery indicator, and the like. A welding-type machine may also include an LCD designed to display one or more menus to a user.
To improve their viewability, LEDs and backlit LCDs are constructed and powered to emit relatively bright light. In this regard, a user can easily distinguish between a lit and a non-lit indicator. However, because of size, thermal, and power constraints, the brightness of the light is constrained. As a result, it may be difficult, in some situations, for a user to appreciate that a particular LED is lit or determine what is being displayed on an LCD.
For example, welders and other welding-type machines are commonly used in outdoor as well as indoor environs. When used in an outdoor environment, the intensity of the ambient light, i.e. sunlight, might be such that a user has difficulty in ascertaining whether a particular LED is lit or have difficulty in reading the alphanumeric characters of an LCD. As a result, increasingly, welding-type machines are being equipped with shades to ease a user's detectability of a lit LED or readability of an LCD when the machine is being used outdoors. While helpful, when the indicator is subjected to direct sunlight, shades have been shown to be inadequate.
It would therefore be desirable to have a indicator whereby a user can easily detect illumination thereof when subjected to direct sunlight.